MXPA97002467A - Machine for buried underwater cable that has an improved appliance for ca placement - Google Patents

Abstract

The present invention relates to a cable laying apparatus that solves many of the problems hitherto associated with existing cable laying mechanisms for underwater buried machines, uses a depressor wheel that is pivotally lifted, located within a shoe of feed that tracks the slot that is cut by the excavator. There are a pair of arched cable guides, one on each side of the depressor wheel, which help in guiding both cables and bodies without allowing anyone to get stuck. When the mounting to which the depressor wheel is connected rises up and back, the guides prevent the cable from escaping while allowing a body to pass through the opening that is

Description

SÜB-AQUATIC CABLE BURIING MACHINE HAVING AN IMPROVED APPARATUS FOR CABLE POSITIONING BACKGROUND OF THE INVENTION The present invention relates to sub-aquatic or submarine cable buried machines. In particular, the invention relates to an underwater cable buried machine having an improved cable laying apparatus, which includes a depressor wheel for guiding the cable into a slot that is cut into the seabed by an excavator. Underwater buried machines are used to bury communications cables at the bottom of the sea, in an effort to protect the cables against damage. These machines dig a slot in the sea bed, under a body of water and simultaneously place a cable inside the slot they have excavated. Burying machines use at least one fixed, simple excavator blade to cut a slot in the seabed, immediately in front of a wire laying mechanism. The cable is then placed inside the groove thus formed so that it is somewhat below the surface of the seabed. After the cable has been placed inside the slot, water pressure and underwater currents eventually cause the vertical walls of the slot to collapse and move the sand and earth into the slot, REF: 24031 thus covering the cable and helping in the total buried operation. A cable placement mechanism should ideally track the slot that is cut by the excavator and should place a cable in that slot. Periodically, however, ie every 32.18 to 80.45 km (20 to 50 miles) a device called a "body" that may contain a repeater or other electronic device is connected to the cable. While the cables are relatively thin, i.e. approximately 1.27 cm (1/2 inch) in diameter, the bodies typically are several centimeters (inches) in diameter and can be up to about 25.4 cm (10-inches) in diameter. Accordingly, it is important that the cable placement mechanism be adapted to handle both the cable and the bodies and it is important that by being able to handle bodies, the cable placement mechanism does not lose its ability to recapture the cable. In addition, it is important to have a cable placement mechanism that does not easily allow the cable to be linked following the passage of a body through the mechanism. In view of the above problems that were not solved by the prior art cable laying mechanisms, an improved cable positioning mechanism that can overcome these problems would be convenient.

SUMMARY OF THE INVENTION In accordance with the present invention, a new design approach has been described after many of the problems to date associated with cable laying mechanisms for existing underwater buried machines. The new design uses an efficient configuration of an oppressor wheel that is pivotally lifted, located inside a cable feeding shoe that tracks the slot cut by the excavator. A pair of arched guide wires, one on each side of the depressor wheel, help in guiding both cables and bodies without allowing anyone to bind. BRIEF DESCRIPTION OF THE DRAWING In the drawing: Figure 1 is a side view illustrating the improved cable laying mechanism of the present invention in a cable buried machine that is traced by a surface ship in a cable laying operation; Figure 2 is a perspective view of the carriage illustrating a cable placing mechanism of the invention installed; Figure 3 is a perspective view of the carriage, without the installed cable placement mechanism; Figure 4 is a perspective view of the depressing wheel assembly; Figure 5 is a perspective view of the top plate of the feed assembly showing the guide rail slots; Figure 6 is a perspective view of the supply shoe; Figure 7 is a side view of the depressor wheel assembly; Figure 8 is a perspective view of the front of the depressing wheel assembly; Figure 9 is a cross-sectional view of a portion of the depressor wheel and the cable guides; and _ Figure 10 is a cross-sectional view of the depressor wheel and the depressor wheel supports. Detailed Description of the Preferred Modality of the Invention With reference to Figure 1, a simplified side view of the cable laying apparatus 10 of the present invention in use in a cable laying machine 12 in a cable laying operation is illustrated. . The cable laying machine 12 is mounted on a marine sled 14 which is towed on seabed 16 by a ship on the surface 18. The trailer is achieved by a combination of umbilical cable / trailer 20. During the towing operation , a communications cable 22 is unwound from a reel 24 in the ship 18. As the sled 14 is pulled forward, an excavator 26 cuts a slot 28 in the seabed 16 and the communications cable 22 is placed inside that slot 28 by the cable positioning apparatus 10 which is located on the rear of a carriage 30 which is fixed to the sled 14, using a four-bar link 32. As will be understood by those skilled in the art, the articulation of four bars 32 allows the carriage 30 to move up and down relative to the sled 12. This allows the excavator 26 and the cable placing apparatus 10, both of which are connected to the carriage 30, and both of the two When it is shown that they extend through the flat bottom of the sled 12, they move up and down relative to the bottom of the sled 12. The four-bar link 32 allows the excavator 26 and the cable laying apparatus 10 to move up on the bottom of the sled 12, when the sled 12 recovers on the platform of the ship 18 for transport or maintenance. In addition, the articulation of four bars 32 can be used to adjust the depth of the slot 28 in case it is necessary due to the constitution of the seabed 16, that is to say if a layer of rocks is found below the surface of the bed 16 to a depth that is less than the depth for normal cable placement. As an example, if the depth of normal cable placement was 30.48 cm (12") and there is a layer of rocks 25.4 cm (26") below the surface of the seabed 16, then the joint of four bars 32 can be adjusted using hydraulic cylinders (not shown) in such a manner that the excavator teeth extend only slightly less than 25.4 cm (26") below the seabed 16, thus preventing damage to the teeth while allowing The buried operation is continued As will be understood by those skilled in the art, the umbilical cable / trailer 20 combination is used both to tow the sled 12, and to transport hydraulic fluid and electrical signals between the ship 18 and the ship. sledge 12. Periodically, ie every 32.18 to 80.45 km (20 to 50 miles) there will be a "body" 34 on the communication cable 22. The body 34 corresponds to a device, such as a repeater, or other electronic device. which is in line with the communications cable 22, but having a diameter that is substantially greater than the diameter of the communication cable 22. As used herein, the term "body" is intended to include any portion of cable 22. which has a diameter substantially wider than the rest of the cable 22. With reference to Figure 2, the perspective view of the carriage 30 showing the cable placing apparatus 10 installed therein, is illustrated. In Figure 3, a perspective view of the carriage 30 without the cable placement apparatus installed., it is illustrated. The cable laying apparatus 10 is constituted by a depressor wheel assembly 36 illustrated in Figures 2, 4 and 7 to 10, and a feed shoe assembly 38 illustrated in Figures 2, 5 and 6. With reference to FIG. Figure 3, the carriage assembly 30 is made of welded steel construction. On the rear part 35 of the carriage assembly 30 there is a pair of rails 37, 39, which are used to place the feed shoe assembly 38. As illustrated in Figures 5 and 6, the feed shoe assembly 38 is constituted by an elongate feed shoe 42 which is used to guide the cable into the slot 28 formed by the excavator 26- (Figure 1), and an upper plate 40, which is the support member for the feed shoe 42. The feed shoe 42 which is closed in front, has an elongated U-shaped opening 44 which is formed to receive the cable 22. The opening 44 extends through the upper and rear part of the feed shoe 42 ( see Figure 6) and is adapted to receive the cable 22 and place it within the slot 28 formed in the seabed 16, as the supply shoe 42 is pulled through the slot 28. In the preferred embodiment of the invention, the closed front of the shoe of feed 42 forms an angle of about 30 ° with the seabed (see Figures 1 and 6) since this has found the optimum angle to minimize the collection of waste by the feed shoe 42. Similarly, the top plate 40 it has an elongated opening 46 that extends through the back of the upper plate 40, and a pair of elongated guide rail slots 48, 50 are formed in the upper plate 40. The cable 22 is fed through the openings 44, 46 and the elongated guide rail slots 48, 50 are used to guide the depressor wheel assembly 36 when pivoted up and out of the supply shoe 42 as will be explained below. __ With reference to Figure 2, the wheel-depressor assembly 36 includes a depressor wheel 52 that fits through the opening 46 in the top plate 40 and extends into the supply shoe 42 in normal cable laying applications. . The depressor wheel 52 is placed in a rotatable depressor wheel assembly 36, illustrated in FIG. 4 to include a depressor wheel shaft 54 about which the depressor wheel 52 rotates. A pair of depressor wheel support clamps 56, 58 , which hang from a pivot wheel mounting support shaft 60, are used to support the depressor wheel shaft 54. The wheel mounting support shaft 60 hangs from the vertical members 31, 33 fixed to the carriage 30 (see Figures). 1 and 2). The wheel mounting support shaft 60 connects the depressing wheel assembly 36 to the carriage 30 and holds the depressing wheel support brackets 56, 58, while allowing them to pivot about the shaft 60. On either side of the depressor wheel 52 , there are arcuate wire guides in the shape of a fang 62, 64. With reference to Figures 8 and 9, the outer peripheries of the cable guides 62, 64 include elongated V-shaped guide rails 63, 65, respectively. The V-shaped guide rails 63, 65 travel in elongated guide rail slots 48, 50 formed in the upper plate 40 (see Figure 5). With reference primarily to Figure 8, the lad? front of the depressor wheel assembly 36 includes a cable guide jumper assembly 89 formed by a formed bait piece having a pair of "flat" portions 90, with a deep V-shaped portion 92 that joins them together. The bridge assembly 89 terminates in a plate 94 that is configured to fit both flat portions 90 and the V-shaped portion 92. The bridge assembly 89 is connected to a support bracket 87 that joins the wheel support brackets. Depressor 56, 58. The cross-sectional shape of the bridge assembly 89, together with the cable guides 62, 64, traverse the guide rail slots 48, 50 in the upper plate 40, ensures that the cable 22 must pass in the Power shoe assembly 38.

A key 86 illustrated in Figure 8 is connected to the clamp 58. A hydraulic cylinder 88 illustrated in Figure 2 is connected to the carriage 30. An arrow (not shown) extends from the hydraulic cylinder 88 and connects to the key 86. Accordingly, hydraulic pressure can be employed to extend the arrow, whether the depressing wheel assembly 36 is pivoted up and back relative to the sled 12 (about the axis 60) when a body 32 must be passed through. of the wheel assembly 36. This pivoting action removes the depressor wheel 52 from the rear part of the feed shoe assembly 38, but the cable guides 62, 64 will continue to run on their guide rails 63, 65 which remain in the slots of guide rail 48, 50 in the top plate 40. Consequently, what was previously a narrow opening (between the bottom of the depressor wheel 52 and the bottom of the feed shoe assembly 38) for the cable 22, can be made a much or greater opening (i.e. between the upper plate 40 and the raised depressor wheel assembly 36) to allow the body 32 to pass, however it still remains as a closed opening from which the cable 22 can not escape. body 32 has passed through the raised depressor wheel assembly 36, the depressor wheel assembly 36 is depressed, and the depressor wheel 52 with the aid of the bridge assembly 89 and the cable guides 62, 64, will recapture the cable 22 in the Feeding shoe 40 for additional cable placement. The levered surfaces 67, 69 in the cable guides 62, 64 (see Figures 4 and 8) assist in guiding the cable 22 and the body 32. With reference to Figures 9 and 10, additional features of the present invention will be explained. As illustrated in cross section, the depressor wheel 52 has a groove 66 formed in its periphery. The slot 66 has a cross section that is configured to receive the cable 22. The wheel also has a series of magnets 70, 72 (Figure 10) and 70, 74, 76, 78, 80, 82, 84 (Figure 7) installed around its edge. While eight magnets are illustrated, in the preferred embodiment of the invention, 16 equally spaced magnets are currently employed. The magnets 70-84 each cause a Hall effect detector 68 (Figure 10) which is connected to the bracket mounted on the support bracket 87 to generate an electrical signal as the depressor wheel 52 rotates. Cable laying operations proceeds at a speed in the range of approximately .93 to 5.56 km (medium to three knots) the combination of the magnets and the detector 68 will supply sufficient data to determine (within approximately .19 km (one tenth of a knot)) the speed at which the wire laying operation proceeds.

Another feature of the present invention is that the shaft 54 includes a "METROX" load pin 55, manufactured from Texas T / M / D. This device 55, which is made of deformimeters, is capable of measuring the residual cable tension, which is the voltage at which the cable 22 is subjected due to the weight of the cable 22 in the water and other factors. Since the tension in a fiber optic cable should be limited to less than about 1,816 kg (4,000 pounds), the data from the detector 55 allows an operator on board the surface ship 18 to check the voltage on the cable 22. The detector Particularly that which is employed in the preferred embodiment of the invention is capable of measuring a tension of up to "approximately 2,451.6 kg (5,400 pounds), ie, a quantity considerably greater than that to which the cable will have to be subjected 22. As will be evident for those skilled in the art, numerous changes can be made to the preferred embodiment of the invention without departing from the spirit or scope of the invention described herein.It is noted that in relation to this date, the best method known to the applicant to carry in practice, said invention is the conventional one for the manufacture of the objects to which it relates, the invention having been described as recited above. as property what is contained in the following:

Claims (16)

1. CLAIMS 1. A cable buried machine characterized in that it has a rotating depressor wheel.
2. 2. The cable buried machine according to claim 1, characterized in that the depressor wheel is placed in a depressor wheel assembly that is pivotally positioned in a carriage assembly.
3. 3. The cable buried machine according to claim 2, characterized in that the depressor wheel assembly further comprises an elongated feeding shoe having a U-shaped opening formed therein, the feeding shoe being adapted to receive a cable to: bury and guide the cable into a slot formed by the buried machine.
4. 4. The cable buried machine according to claim 3, characterized in that the U-shaped opening is closed in the front of the supply shoe and open in the upper and rear part of the supply shoe.
5. 5. The cable buried machine according to claim 4, characterized in that the depressor wheel fits inside the opening formed in the upper part of the supply shoe.
6. 6. The cable buried machine according to claim 5, characterized in that the depressor wheel rotates on a depressor wheel axis, and the depressor wheel axis is connected at either end of a pair of depressor wheel bearing members.
7. The cable buried machine according to claim 6, characterized in that the depressing wheel support members are pivotally supported by a wheel mounting support shaft which is connected, at each end with a pair of supporting members depressor assembly fixed to the car. __
8. 8. The cable buried machine according to claim 8, characterized in that the depressor wheel assembly further comprises a pair of arcuate cable guide members that are connected to depressor wheel bearing members.
9. The cable buried machine according to claim 7, characterized in that the cable guiding members include guides formed around their peripheries including guide rails which are adapted to travel in a pair of guide rail slots formed in the part top of the feeding shoes.
10. 10. The cable buried machine according to claim 9, characterized in that it also comprises a cable guide bridge assembly formed between the cable guide members.
11. The cable buried machine according to claim 10, characterized in that it also comprises means for rotating the depressor wheel assembly backwards and upwards out of the supply shoes, whereby the opening formed therein is sufficient to allow let a body pass
12. 12. The cable buried machine according to claim 1, characterized in that it also comprises means to calculate the speed at which the machine runs on the seabed.
13. 13. The cable buried machine according to claim 12, characterized in that the means comprise a plurality of magnets connected to the depressor wheel and a detector that can sense the passage of a magnet.
14. 14. The cable buried machine according to claim 13, characterized in that the detector is a Hall effect detector.
15. 15. The cable buried machine according to claim 1, characterized in that it also comprises means for detecting the tension in the cable.
16. 16. In addition, it comprises a depressor wheel axis around which the depressor wheel rotates, wherein the means for detecting the tension in the cable comprise extensimeters connected to the depressor wheel axis.